Research Article |
Corresponding author: Yrjö Haila ( yrjo.haila@tuni.fi ) Academic editor: Lyubomir Penev
© 2014 Yrjö Haila, Klaus Henle.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Haila Y, Henle K (2014) Uncertainty in biodiversity science, policy and management: a conceptual overview. Nature Conservation 8: 27-43. https://doi.org/10.3897/natureconservation.8.5941
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The protection of biodiversity is a complex societal, political and ultimately practical imperative of current global society. The imperative builds upon scientific knowledge on human dependence on the life-support systems of the Earth. This paper aims at introducing main types of uncertainty inherent in biodiversity science, policy and management, as an introduction to a companion paper summarizing practical experiences of scientists and scholars (Haila et al. 2014). Uncertainty is a cluster concept: the actual nature of uncertainty is inherently context-bound. We use semantic space as a conceptual device to identify key dimensions of uncertainty in the context of biodiversity protection; these relate to [i] data; [ii] proxies; [iii] concepts; [iv] policy and management; and [v] normative goals. Semantic space offers an analytic perspective for drawing critical distinctions between types of uncertainty, identifying fruitful resonances that help to cope with the uncertainties, and building up collaboration between different specialists to support mutual social learning.
Uncertainty, biodiversity science, biodiversity management, biodiversity policy, semantic space, dimensions of uncertainty, social learning, learning cycle
Uncertainty is an essential ingredient of science, manifested in all phases of conducting research, drawing conclusions, and putting the conclusions into societal practice (
This is insufficient. Biodiversity is such a multidimensional and complex issue that different sorts of uncertainties are inherent in many dimensions of the ecosystems themselves and of biodiversity research. Specifications are needed as to what, precisely, is uncertain, what is the reason for the uncertainty, and whether the uncertainty matters. Further below, we use the notion of semantic space to explore key aspects of uncertainty in the context of biodiversity science, policy and management (see also
Biodiversity is a knowledge intensive concept. The concept was conceived by biologists worried about the consequences of accelerating human-induced changes in the ecological conditions of the Earth; the story is well known (
Let us add a clarification on this point. There is nothing uncertain in the assertion that biological diversity is a critical feature of the life-support system of the Earth, to use Eugene P. Odum’s phrase (
There is a deep ambiguity in the human ecological predicament: whatever we do we change the environment, and we cannot avoid also detrimental effects – in fact, we often do not know precisely, what is detrimental. Furthermore, what is detrimental in one set of conditions may be favourable in another set of conditions. Variability in mechanisms that maintain soil productivity provides examples: what works at one place may be positively harmful somewhere else. In other words, the relationship between generality and precision needs concern. The situation resembles that encountered in debates about climate policy (
To chart the whole field, two round-table discussions were held at Helmholtz Centre for Environmental Research, UFZ, Leipzig, in autumn 2011 under the title Exploring uncertainties in biodiversity science, policy and management. The perspective was pragmatic: the aim was to produce an overview from a bottom-up perspective on how natural and social scientists involved in biodiversity research have come across uncertainty in their working practices and how they have coped with it. We dubbed the domain of the workshop biodiversity praxis (
The work of
For assessing different types of uncertainties in scientific knowledge
In the paper that follows this introductory essay we present the materials of the first workshop, held on 3–4 November 2011. Most of the 18 participants were working within the auspices of the EU 7th framework project SCALES (Securing the Conservation of Biodiversity across Administrative Levels and Spatial, Temporal and Administrative Scales) (
The SCALES project offered a promising framework for the endeavour. It is broad and ambitious enough to provide a good overview of themes for which uncertainty matters. Furthermore, the project addresses explicitly uncertainty in several research tasks. Another workshop was organized on 7–8 December. The compilation of papers collected in this special section of Nature Conservation includes, in addition to this introductory text, a thematic overview of the November workshop (
Uncertainty needs not be formally “defined”. It is best regarded as a cluster concept, which gets different specific shapes in different contexts. In general terms, uncertainty pertains to the cognitive relationship of human agents to choices on what they do or prepare to do in a particular situation at a particular time. The inherent complexity of real world systems humans are faced with is a major source of uncertainty. In this broad sense uncertainty has a pervasive presence in all practical decisions people make both in daily routines and when getting prepared for the future either individually or as agents in institutions (
Our perspective implies that uncertainty has an ambiguous character. Uncertainty comes in many different guises, and in any particular situation it may be difficult to pin down what, specifically, is uncertain. Economists, in particular, have been aware of this ambiguous nature of uncertainty – quite understandably, in fact, as they have been interested in human economic actions oriented toward future that is never known in advance (
The dream of measurability of future events was given a formal supporting argument by French mathematician Pierre Laplace in the 18th century. He claimed that a demon with perfect knowledge of the world would be able to predict the future with perfect accuracy. However, the Laplacean dream has been put to rest by the research on nonlinear dynamics that had its origin in the work of Henri Poincaré in the late 19th century. Since then, both formal-mathematical and conceptual studies of complexity, non-linearity and chaos have made considerable progress. With the help of the huge increase in computing power during the last few decades, a lot has been learned about qualitatively specifiable features of uncertainty in different types of chaotic systems (e.g.,
The general lesson is: uncertainty does not mean that anything can happen anywhere anytime. In other words, the set of possible ways a particular system can change is bounded, but the tightness of the bounds is relaxed with increasing time (
In practical terms, the model adopted of the system of interest is critical. Philosopher
It is useful to think of a semantic space in terms of dimensions, as always is the case with abstract spaces. The dimensions of a semantic space can be identified using the idea of a contrast space as a means.
In accordance with the contrast space perspective, we adopted a few distinctions that were used as a background for the workshops. These were regarded pretty much as self-evident in the discussion. The first such distinction was between uncertainty and risk. Economists have been well aware of this contrast since the 1920s, as we noted above. The second distinction was between epistemic uncertainty pertaining to knowledge and stochastic uncertainty pertaining to ontology of the world, customarily drawn in the context of sensitivity analysis (e.g.,
The three distinctions presented above correspond to three dimensions of the semantic space of uncertainty. The dimensions are relatively independent of one another. It is, for instance, perfectly legitimate to ponder upon type I vs type II error irrespective of whether the uncertainty assessed is epistemic or ontological. When organizing the workshops, we were mainly interested in substance-specific dimensions of uncertainty in biodiversity research. We present a preliminary model of the semantic space in the final section of this paper.
The general features of unpredictability presented above are pertinent as regards the ecological realm where conditions are changing all the time in unpredictable ways. In its youth in the late 19th century, the science of ecology viewed nature through a “balance of nature” metaphor, but it was soon realized that ecological conditions are in a continuous change. Alfred Lotka’s classic Elements of Physical Biology (
To approach the semantic space of uncertainty of biodiversity praxis, a comparison between biodiversity and climate change is instructive. There is a clear difference between these fields stemming from the different nature of the medium: the Earth’s atmosphere is a unified geophysical system whereas the biosphere is divisible into different sections or subsystems, geographically, taxonomically and ecologically. Furthermore, the divisions are descriptively complex (
A practical comparison clarifies the example. When compiling background data on climate change, it is possible to take estimates of green-house gas discharges of single countries such as, say, China, Canada and Guatemala, and extrapolate the effect of each of them to the global atmospheric balance. In the case of biodiversity, no comparable extrapolation is possible. Also the social consequences of biodiversity loss are much more unequivocal than of climate change. The question of contextuality is raised: symptoms, probable consequences, and policy implications of threats vary in a much more context-specific fashion in biodiversity policy than in climate policy (not denying that socio-economic differences across countries are relevant in climate policy, too).
The driving motivation of the workshops at the UFZ was the need to specify types of uncertainty in biodiversity praxis. There is no single way to reach this goal. We have to proceed along several mutually complementary lines. A good start is to ask the three simple clarifying questions we referred to in the opening section of this paper: What, precisely, is uncertain? Why, specifically, is this thing uncertain? And finally, does the uncertainty matter, and if it does, in which sense? Every ecologist with field-work experience can come up with examples of such a chain of questions, pertaining to a specific research project, for instance, the taxonomic composition of the samples collected, or the correspondence between the samples and the populations sampled, and so on (
However, such a purely empirical specification of uncertainty covers only one theme at a time. Generalizable concepts are needed. More interesting distinctions can be drawn by utilizing a theory of conceptual spaces developed by cognitive scientist
Gärdenfors demonstrates the differences between the three types of representation using as an example a jungle where people try to find their way. The first form, ‘subconceptual’ representation consists of what they come across and record, often without articulation: “dynamic interactions between people and their environment” (p. 34). The second, ‘conceptual’ representation gives order to what they record, using abstract categories; in the example: “representing traveling information in a spatial form” (p. 34). The third, ‘symbolic’ representation is used when the road is marked with name-tags that will be recognized and interpreted in a consistent way by the people involved, “it is also required that there is common knowledge of what places the names refer to” (p. 35).
The three types of representation can be affiliated with three types of uncertainty. Uncertainty on the subconceptual level is about whether observations are recorded properly. The conceptual level relates to whether the spatial representation is usable. The symbolic level relates to the consistency of the shared knowledge inscribed in the collection of name-tags. These distinctions are applicable to biodiversity science in a straightforward fashion: subconceptual is about methods used in collecting data, conceptual is about patterns detected in the data, and symbolic is about the credibility and social relevance of the conclusions.
To make the analogy more concrete, let’s note that Gärdenfors’ distinctions have a clear affiliation with the standards adopted to mitigate different types of errors in empirical reasoning. Type I and type II errors correspond to the conceptual level. The decision made as to the type of error that is of main concern has a major influence on how the resulting pattern may be used in further research or in management. Statistical tests aiming at avoiding type II error (assuming no effect while there actually is an effect) customarily accept 20% error rate as a standard, but this may be too strict in the case of useful rules of thumb that can be used in management, for instance (
We use the analogy between cognitive types of representation outlined by Gärdenfors and dimensions of uncertainty when constructing a preliminary model of the semantic space of uncertainty in the final section.
We referred above to economists as pioneers in thinking explicitly about the implications of the unpredictability of future in the social domain. Their thinking about uncertainty has advanced a lot since the groundlaying work of Knight and Keynes almost a century ago and offers some further lessons.
In particular, the view on the nature of risks in the markets has undergone great changes in the last half a century or so. Journalist Justin Fox (2009) who is well informed in recent economic history tells the story by tracking the development in the views of academics in economics and finance up to the first decade of the 21st century. Briefly put, there have been two main issues that dominate the story: first, the rationality (or not) of the markets, and second, the possibility (or impossibility) to beat the markets by a clever investment strategy. One of the cornerstones in the discussion has been the view, generally held since the mid-20th century, that variation in market values follows random walk, at least in the short run. It is consistent with the rational markets hypothesis through a variant of the law of large numbers: given enough traders, all discrepancies in market valuation of different assets supposedly even out – almost in real time, given efficient enough investment tools. This argument is in line with the view promulgated by free markets champions such as Frederick von Hayek and Milton Freedman that the markets constitute the best possible means to handle economic information. As Fox (2009) shows, models used to analyze variation in market values have become incredibly sophisticated in the course of the last few decades.
The efficient markets hypothesis makes the distinction between risk and uncertainty all but vanish. In the domain of random walk, there are no qualitative distinctions between types of uncertainties. Everything is akin to quantifiable risk and can be taken into account in advance, given good enough models.
However, the economic life in the last three decades has not agreed with these assumptions. The recessions of 1987 and 1998 and the dot.com bubble in the early 2000s, not to speak of the latest crisis that the world plunged into in 2008, contradict the rational markets hypothesis and the models built upon that hypothesis. In other words, parallel to the development in thinking about the markets, the nature of radical systemic uncertainty inherent in the markets has been clarified. There is an element of ontological uncertainty in this setting: new forms of financial assets change the behaviour of market actors, which changes the behaviour of the markets in turn. In fact, Daniel Kahneman and Amos Tversky pointed out this possibility already decades ago (see the essays in
There is another, even more important implication of the change in thinking about the economic life that is breaking through the established orthodoxy: an emphasis on contextuality. Context-specificity of human reasoning itself is the starting point of
If uncertainty is inherently contextual, making sense of uncertainty in specific situations requires that we take into account several aspects of cognitive work and social reality. On the cognitive side, a good starting point is offered by the work of
Hence, an appropriate framing of problems includes an assessment of factors that back arguments concerning the nature of the problem, one way or another.
Fisher’s scheme offers a good starting point to elaborate upon types of uncertainty related to specific issues of biodiversity protection. As an example, consider managing human wildlife conflicts (
We present a suggestion on how the schemes of Gärdenfors and Fischer fit together in Figure
Nobel economist Wassily Leontief (1971) expressed his view on the relationship of theoretical and empirical research in economics as follows:
“True advance can be achieved only through an iterative process in which improved theoretical formulation raises new empirical questions and the answers to these questions, in their turn, lead to new theoretical insights. The “givens” today become the “unknowns” that will have to be explained tomorrow. … An example of a healthy balance between theoretical and empirical analysis and of the readiness of professional economists to cooperate with experts in the neighbouring disciplines is offered by agricultural economics as it developed in this country over the last fifty years. … Close collaboration with agronomists provides agricultural economists with direct access to information of a technological kind. When they speak of crop rotation, fertilizers, or alternative harvesting techniques, they usually know, sometimes from personal experience, what they are talking about. … While centering their interest on only one part of the economic system, agricultural economists demonstrated the effectiveness of a systematic combination of theoretical approach with detailed factual analysis.”
Leontief’s passage is a clarion call to an integrative knowledge strategy. The spirit is identical with our view on the challenge that biodiversity praxis is facing. But we want to get further than only note the similarity. The next step to take is to identify main dimensions of specialized work that need to be integrated together in biodiversity praxis. In the preceding sections we took up two conceptual schemes that can be used to this end: the layers of cognitive space presented by Peter Gärdenfors, and the layers of social and political warrants of claims-making specified by Frank Fischer (see Fig.
It seems natural to order the dimensions from more concrete to more abstract. In the beginning, there is the data, and issues concerning representativeness, methodological consistency, and so on: the “preconceptual” level in the scheme of Gärdenfors. Primary data have to be compressed so they give relevant information for the issue at hand. Proxy (or indicator) is a shorthand for this. Proxy is a representation, which raises the question of adequacy: does it reliably stand for the phenomenon of interest? A whole range of proxies have been used in biodiversity research, from very general ones, such as species number and habitat area, to very specific ones, such as the presence of indicator or “umbrella” species. There is a rich discussion on the relative merits of different proxies (
But the credibility of a particular proxy does not depend on the empirical background alone, as important as this is: background concepts enter the picture. A workable proxy requires conceptual support. The situation is utterly familiar in biodiversity research, as it already was in the early stages of exploratory research on species–area and species–abundance -patterns from the early 20th century on. This is the “symbolic” dimension of Gärdenfors: a question about the coherence of the way the understanding of the problem is phrased. Schematic models, such as the species–area curve, obtain the role of symbols in scientific work (
The last two dimensions in Figure
The scheme in Figure
First of all, there are interactions between the axes of the semantic space presented in Figure
As a means to specify further what is going on at interesting zones of transformation, we take up the idea of closure. As regards a knowledge-intensive issue, such as biodiversity protection, closure of knowledge and closure of policy go hand in hand; this view builds upon
Another aspect of the model presented in Figure
The normative backing is all-important, as was made clear in the workshop discussion (
As a final note: in the spirit of Leontief’s recommendation cited above, a general consensus grew out of the discussions at the Leipzig workshops that successful and meaningful coping with uncertainty depends ultimately on a learning cycle that covers the whole recursive chain cycling through science–management–policy–science. We elaborate a learning cycle view in the concluding section of the joint workshop report
A grant from the Academy of Finland (136661) facilitated Yrjö’s work on this project, including a stay at UFZ in Leipzig in October-December 2011. The participation of members of the SCALES project in the November workshop was supported by the SCALES project (Securing the Conservation of biodiversity across Administrative Levels and spatial, temporal, and Ecological Scales) funded by the European Commission as a Large-scale Integrating Project within FP 7 under grant #226 852 (